Servidores de rack idénticos apilados en un carro metálico, pendientes de montar, delante de un rack a medio poblar

Corosync adds 650 milliseconds per node: the clock your upgraded cluster is still carrying

The time a Proxmox cluster takes to re-form membership after losing a node is not fixed: it grows by 650 ms for every node you add, and on factory values a 29-node cluster reaches 45.21 seconds — exactly where the documentation itself asks you to fix it, before the 60-second watchdog starts rebooting healthy nodes. Proxmox VE 9.2 lowered it to 125 ms, but only when the cluster is created: clusters upgraded from 8 to 9 keep the old value.

Proxmox High availability Infrastructure

Read more →

Servidor de almacenamiento abierto en un rack con las bahías de discos a la vista y una unidad extraída de su carro

27 Aug 2026 9 min read

In Ceph, capacity is not set by the cluster: it is set by the fullest disk

A single OSD above 95% stops writes across the whole cluster even while "ceph df" still shows dozens of free terabytes. The three default thresholds (0.85 / 0.90 / 0.95), why the mechanism that repairs switches off five points before the one that serves, and the capacity calculation with one node missing that almost nobody runs: with four nodes the ceiling is 71 points, and 67 if you want the rebuild to actually finish.

Ceph Storage Proxmox

Read more →

Portal de un edificio antiguo con una única puerta acristalada, el portero automático y los buzones metálicos

26 Aug 2026 8 min read

Your identity provider is not an application: it is infrastructure

On Monday 24 August, at 03:38, a denial-of-service attack began against Norway's shared government digital platform. Ten public services went down and several had nothing wrong with them: the door everyone goes through had jammed. Digdir writes on its status page that <code>eSignering</code> was unavailable "because of the limitations in ID-porten", and also that the services were "stable with the limitations that have been put in place" — part of the outage was put there by the defenders. Why single sign-on is still the right call, what changes when the door becomes infrastructure, and the three questions that reclassify it.

Identity Infrastructure Continuity

Read more →

Pulsador de parada de emergencia en una pared: el nodo que se apaga a sí mismo para que el clúster pueda seguir

12 Aug 2026 7 min read

Proxmox HA does not prevent downtime: it shortens it (and sometimes causes it)

Proxmox VE's own documentation sets the ceiling: about 2 minutes of error detection and failover, and no more than 99.999% availability. What really happens when a node dies (a cold start, not a live migration), why a healthy node reboots itself 60 seconds after losing quorum, the requirements everybody skips, and when we do not deploy HA at all.

Proxmox High Availability Virtualization

Read more →

142,000 tickets

400,000 users

9 Jan 2026 17 min read

Anatomy of a High-Demand Ticketing System: How Rosalía's LUX Tour sold 142,000 tickets without collapsing

Deep technical analysis of Rosalía's LUX Tour ticketing system. 400,000 users, 142,000 tickets, virtual queues, Redis, WebSockets, Circuit Breakers and the architecture that made selling 8 concerts in 2 hours possible.

Ticketing Architecture Redis

Read more →

everyWAN Blog

Corosync adds 650 milliseconds per node: the clock your upgraded cluster is still carrying

In Ceph, capacity is not set by the cluster: it is set by the fullest disk

Your identity provider is not an application: it is infrastructure

Proxmox HA does not prevent downtime: it shortens it (and sometimes causes it)

Anatomy of a High-Demand Ticketing System: How Rosalía's LUX Tour sold 142,000 tickets without collapsing

Subscribe to our newsletter